Bituminous sealing materials are in general formed of two parts:
a part which will subsequently remain visible,
a part which will serve for assembling elements together so as to form a continuous membrane preventing water from entering.
The invention relates to protecting the part which serves for assembling elements together.
The part which serves for joining two separate elements together to form therefrom a continuous element will be called jointing zone in what follows.
A jointing zone has in general the same composition as the rest of the material, except that all the elements are removed therefrom which, considering the sealing means contemplated, may hinder use thereof and, if such be the case, elements promoting this use are added thereto.
For example, sealing materials proposed in rolls, comprise the sealing element itself, the surface protection against climatic agressions (UV, temperature, water, etc.) and the jointing zone formed on the edge of the sealing element.
The method for assembling bituminous material sealing elements in accordance with the invention is characterized in that, on the edge of an element, preferably stripped, forming the jointing zone there is placed a sheet of particular non-woven fibers on which is applied by overlapping the edge of the adjacent element.
The surface protection then appears continuous.
Sealing of the two elements together is achieved by any known means, such as hot bitumen, adhesive or by melting with a blowlamp provided for this purpose.
However, this jointing zone, before use, will have to be stored in rolls without the turns sticking together.
It will also have to be manufactured economically; since the price of sealing materials is low, many of the solutions used in the industry of permanent adhesives (labels and tapes, for example) are not easily usable.
The problem which arises for this jointing zone is: what type of protection to use on this jointing zone which does not hinder the final sealing but allows the sealing roll to be handled and stored without problems before sealing.
Finally, the jointing zone must be sufficiently crush-resisting for the roll of finished product will be stored on the jointing zone side.
Most of the solutions used are not technically perfect and/or economically viable. The following protections have thus been used:
Powdered silica or other powdered minerals such as talc, slate, etc. This very economical solution does not perform very well from the use point of view, since the mineral forms a screen. Furthermore, the stockability is not perfect for sticking between turns in hot weather is likely to occur.
Polyolefin films. This solution is economical and presents good protection against sticking between turns. Unfortunately, the material can only be sealed with a blowlamp and not with hot bitumen or adhesive, which considerably restricts use thereof.
Strippable protections, such as silicon coated paper and similar. This solution is perfect from the protection point of view, but not as good from the point of view of use for it requires the protection to be removed and destroyed. Moreover, it is not economical.